Efficacy Assessment of Wide-Gap Torque-Type Rheometer for Evaluating Shear-Rate-Dependent Viscosity of Rice Porridge

Rheological property is a key factor not only in how consumers choose and enjoy foods, but also in ensuring the safe eating and swallowing for dysphagia patients. The rheological measurements of fluid foods containing millimeter-sized ingredients, however, have still been challenging due to the limitations of a standard torque-type rheometer. We herein examine the efficacy of a wide-gap torque-type rheometer for evaluating shear-rate-dependent viscosity of heterogeneous fluid foods containing millimeter-sized ingredients. In addition to numerical validation using a shear-thinning fluid obeying the power law model, the apparent flow curves of silicone oil and carboxymethyl cellulose aqueous solution were compared with those obtained by the standard rheometer. It was also confirmed that the shear-thinning properties of plain, egg, and bean porridge well match those identified by the recently developed velocity-profiling-assisted rheometry. These results reinforce the wide-gap torque-type rheometer to be practical for probing the rheology of the complex fluid foods.